It ruled that one police officer had acted recklessly in offering immunity to witnesses at a public meeting.

Ms Mahmood said a public inquiry was now the only way to ensure the truth came out.

She said: “On the night these young men died it was Haroon’s father, Tariq, who stood up and appealed for calm. It was Tariq who stopped further deaths. All he and the families want and deserve is justice. So far they have had none.

“The court case yielded not a single conviction; the IPCC report was an abject failure. And therefore in this case we need a public inquiry to look into this if we are to get justice.

“So far our requests to the Government have fallen on deaf ears.”

In a letter to Theresa May, the Home Secretary, she warned: “Three years after the brutal murder of his son, Mr Jahan has quite understandably lost faith in the justice system.

“His son was killed in plain view.

“Eight men were prosecuted but none were convicted in a trial which almost collapsed because of issues with the police investigation.”